A Resistance-change memory elements, such as a Magnetic Tunneling Junction (MTJ) element, change the resistance state thereof when a write current is supplied thereto. However, the timing at which the resistance state changes varies element by element. Hence, for supplying a write current to resistance-change memory elements, a sufficient time that allows the memory element to change the resistance state is ensured. According to this scheme, however, the write current is still supplied to the memory elements even after the resistance state of the resistance-change memory elements have changed (even after data write has completed), and thus a wasteful power consumption is made.
Non Patent Literatures 1 to 4 disclose technologies of detecting a completion of data write in resistance-change memory elements. Non Patent Literatures 1 to 3 disclose devices which intermittently read data stored in memory elements, and which detect the completion of write upon reading of the data to be written. Non Patent Literature 4 discloses a device that detects the completion of data write when the voltage at one end of a resistance-change memory element changes to a voltage corresponding to the data to be written.